Phototherapy Side Effects

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Phototherapy is a medical procedure in which the skin is exposed to ultraviolet (UV) light in an effort to treat specific skin conditions. If you have psoriasis, eczema or other skin diseases, your doctor may recommend treatment with phototherapy. Before beginning treatment, discuss any questions or concerns you have regarding this procedure and any related side effects with your physician.


Exposure to UV light during phototherapy may cause reddening of the skin—a condition called erythema. This is a common occurrence and will typically resolve within several hours or days following initial treatment. Prolonged exposure to UV light during phototherapy treatment may burn or damage the upper layer of skin. If this occurs, you may experience sensitivity, pain or itching at the site of treatment. Such symptoms will resolve within several days following exposure. If your skin is severely irritated, speak with your doctor to discuss the use of over-the-counter products that may alleviate these symptoms.


Phototherapy may cause certain people to develop a headache during or following treatment. The headache may be mild or moderate in severity and will typically resolve within a few minutes or hours after treatment is completed. Over-the-counter pain medications, such as acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) may be recommended to help alleviate headache symptoms.


After you receive a phototherapy treatment, you may feel excessively tired or fatigued. If this occurs, you may benefit from having someone accompany you to your appointment so that you do not need to be concerned about driving home while you are fatigued.


If you receive phototherapy near or on your face, you may be at an increased risk of developing cataracts. This eye condition can cause double, blurred or cloudy vision to develop in certain people. Your doctor will provide you with protective eyewear to use during treatment to prevent potential damage to your eyes.


Certain people—especially infants and children—may experience diarrhea following phototherapy treatment. Diarrhea is a condition that results in the excretion of loose or watery stools; it can also cause abdominal cramping or bloating in certain people.

Premature Aging of the Skin

Recurrent or prolonged phototherapy treatment may cause premature aging of the skin in certain people, reports the Beth Israel Deaconess Medical Center in Boston, Massachusetts. You may develop dry or itchy patches of skin at the site of phototherapy treatment. Wrinkles, age spots or freckles may also appear on the regions of skin that have been exposed to UV phototherapy.